Coronary artery disease is the most common heart disease, with about 20.1 million adult patients in the United States and causing about 0.38 million deaths in 2022 [1]. CAD is treated with CABG surgery, and almost 0.4 million surgeries are done each year [2].
CABG surgery and associated postoperative complications
CABG is a high-risk surgery that leads to many post-operative complications, including chest wound infections, pneumonia, graft failure, pulmonary hypertension, breathing muscle dysfunction, lung dysfunction (atelectasis), etc. These complications lead to morbidity, prolonged ICU stays, and mortality in the patients [3].
Role of Physiotherapy in CABG Recovery
Preoperative or postoperative physiotherapy interventions can decrease the risk of developing postoperative complications and reduce the length of hospital stay in heart surgery patients [4]. Clinicians advise these patients on various interventions, alone or in combination, such as endurance training, resistance training, and respiratory muscle training.
Respiratory Muscle Training for CABG Patients
Recently, RMT has become popular for bypass surgery patients. During post-operative treatment, it helps them increase their breathing muscle strength and exercise capacity. It can be easily performed even after surgery, ultimately decreasing the chances of post-operative complications.
Clinical research has demonstrated that RMT improves breathing muscle strength and reduces pulmonary complications (problems related to the lungs) in heart surgery patients.
In 2023, a meta-analysis was conducted to systematically analyze the existing clinical research on the impact of RMT on patients who had CABG surgery [5].
Meta-Analysis: Investigating the Effects of RMT on CABG Patients
Five researchers from three universities in China (Wuhan and Changchun) conducted a systemic review and meta-analysis investigating the effects of RMT in patients who underwent CABG surgery [5]. They screened 351 studies and selected 12 for this meta-analysis, which included 918 heart patients. The included studies were randomized control trials, and their quality was assessed using the PEDro scale.
They conducted this extensive analysis on the effects of RMT on inspiratory and expiratory muscle strength, pulmonary (lung) function, postoperative pulmonary complications, duration of hospital stay, and fitness level in patients with a history of heart surgery.
Results of meta-analysis
The results of this analysis revealed promising facts about RMT benefiting the patients undergoing heart surgery.
Inspiratory muscle strength improvement
The analysis of 4 studies revealed preoperative RMT and analysis of 4 studies showed postoperative RMT improved inspiratory muscle strength in patients undergoing heart surgery. Three studies demonstrated a significant increase in the inspiratory muscle strength by preoperative and postoperative RMT compared to control groups.
Expiratory muscle strength improvement
Two studies included in this analysis indicated that postoperative RMT increased expiratory muscle strength.
Pulmonary function improvement
Two studies evaluated respiratory functions, and their analyses revealed a significant improvement in breathing function with preoperative RMT.
Reduction in postoperative pulmonary complications
Four studies assessed postoperative pulmonary complications, and the analysis showed that patients who received preoperative RMT had a reduced risk of PPCs.
Reduction in hospital stay
The analysis of three studies with preoperative RMT demonstrated a reduction in the duration of hospital stay, while three studies with postoperative studies showed a decrease of 1.55 days.
Exercise capacity improvement
Two studies assessed the capacity of exercise, indicating a significant improvement in exercise tolerance with postoperative RMT as compared to usual care patients.
Discussion
This meta-analysis provides insights into the benefits of preoperative or postoperative RMT for patients undergoing heart bypass surgery. A previous systematic review demonstrated similar results, such as improvements in respiratory muscle strength and pulmonary functions along with a reduction in the incidence of PPC and hospital stays in cardiac surgery patients [6].
Given its benefits in rehabilitating heart bypass surgery patients, RMT should be considered a standard preoperative and postoperative intervention and should be included in clinical guidelines for CABG rehabilitation.
Conclusions
RMT (preoperative or postoperative) is effective in patients who undergo coronary artery bypass graft surgery by improving respiratory muscle strength, exercise capacity, and pulmonary function and decreasing postoperative pulmonary complications and ICU stay.
